Systems and methods for fluid management

ABSTRACT

A system includes an implantable device including a pump to pump the fluid from the peritoneum to the bladder via respective catheters, control circuitry, battery and transceiver; a charging and communication system configured to periodically charge the battery and communicate with the implantable device to retrieve data reflective of the patient&#39;s health; and monitoring and control software, suitable for use with conventional personal computers, for configuring and controlling operation of the implantable device and charging and communication system. The monitoring and control software allows a treating physician to remotely adjust the volume, time, and frequency with which fluid is pumped from the peritoneal cavity to the bladder based on the data reflective of the patient&#39;s health.

I. CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/965,727, filed Apr. 27, 2018, now U.S. Pat. No. 10,569,003, which isa continuation of U.S. patent application Ser. No. 14/077,005, filedNov. 11, 2013, now U.S. Pat. No. 9,956,336, which is a continuation ofU.S. patent application Ser. No. 13/397,498, filed Feb. 15, 2012, nowU.S. Pat. No. 8,585,635, the entire contents of each of which areincorporated herein by reference.

II. FIELD OF THE INVENTION

This application relates to apparatus and methods for removing productsfrom the body.

III. BACKGROUND OF THE INVENTION

Approaches have been developed for cleansing the blood of toxins andwaste products based on peritoneal dialysis, in which dialysate isintroduced into the patient's peritoneal cavity. For example, U.S. Pat.No. 7,169,303 to Sullivan describes passing dialysate into a patient'speritoneal cavity, then withdrawing the dialysate from the peritonealcavity and passing the withdrawn dialysate through an extracorporealtreatment system that includes a sorbent suspension for toxin removal.

U.S. Pat. No. 8,012,118 to Curtin describes a wearable dialysis systemfor removing uremic waste metabolites and fluid from a patient sufferingfrom renal disease, in which a small external pump continuouslyrecirculates peritoneal dialysis solution between the peritoneal cavity,where uremic waste metabolites diffuse through the peritoneal membraneinto the dialysis solution, and a replaceable cartridge that cleans thesolution and that may be replaced when the various layers becomesaturated. Curtin describes that albumin can be added to the peritonealdialysis solution in the removal of protein-bound toxins and that abacterial filter may be used to remove bacterial contamination from thesolution. Curtin further describes that the fluid loop includes areplaceable drain container that drains excess fluid that has been addedto the peritoneal dialysis solution through osmosis from the patient'sbody. A plurality of hollow fiber membranes may be connected to thepatient's blood stream via vascular grafts to remove excess fluid fromthe blood stream, and that such excess fluid may be drained to thepatient's bladder.

In view of the above-noted drawbacks of previously-known systems, itwould be desirable to provide methods and apparatus for using animplantable device having a minimum number of parts requiringreplacement, avoids the need for the patient to handle multiple types offluid, and reduces the risk of infection, and allows for continualphysician involvement.

IV. SUMMARY OF THE INVENTION

The present invention overcomes the drawbacks of previously-knownsystems and methods by providing a system that automatically andautonomously provides into a patient's peritoneal cavity, and thenremoves products therein to the patient's bladder, with reduced burdenon the patient. The system of the present invention also periodically orcontinually provides data reflective of the patient's health to thetreating physician, who may remotely adjust the patient's treatmentbased on changes in the patient's health.

The system of the present invention preferably comprises a reservoircontaining a fluid and configured to provide the fluid to the patient'speritoneum; a peritoneal catheter configured for implantation in thepatient's peritoneum; and a bladder catheter configured for implantationin the patient's bladder. The system further preferably comprises animplantable device including a pump, a controller, a battery and atransceiver, and being configured to pump the fluid in the peritoneum tothe patient's bladder via the peritoneal catheter and the bladdercatheter; a charging and communication system configured to periodicallycharge the battery of, and communicate with, the implantable device; andmonitoring and control software, suitable for use with a conventionalpersonal computer, for configuring and controlling operation of theimplantable device and charging and communication system. Preferably,the monitoring and control software is available only to the treatingphysician, such that the patient generally interacts with theimplantable device only via the charging and communication system forpurposes of recharging the implantable device. The monitoring andcontrol software may be used to monitor the patient's health and toadjust the parameters of the treatment if needed, e.g., by increasing ordecreasing the flow rate into or out of the peritoneal cavity, thevolume, the frequency of pumping, and/or the time the fluid remainswithin the peritoneal cavity.

In some embodiments, the reservoir is configured for external use.Optionally, the system includes an external pump configured tofacilitate flow of the fluid from the reservoir to the patient'speritoneum. The system may include a belt configured to secure thereservoir to the patient's body, and the reservoir may include at leastone pouch arranged along the length of the belt. A reservoir cathetermay be coupled to the reservoir and to the implantable device, the pumpfurther being configured to pump the fluid from the reservoir to thepatient's peritoneum via the reservoir catheter and the peritonealcatheter. First and second valves may be provided in operablecommunication with the implantable device, the second valve beingconfigured to be actuated so as to prevent flow from the bladder to theperitoneum when the fluid is pumped from the reservoir to theperitoneum, the first valve being configured to be actuated so as toprevent flow from the peritoneum to the reservoir when the fluid ispumped from the peritoneum to the bladder.

In other embodiments, the reservoir is configured for internalimplantation and comprises a port configured to receive fresh fluid. Areservoir catheter may be coupled to the reservoir and to theimplantable device, the pump further being configured to pump the fluidfrom the reservoir to the patient's peritoneum via the reservoircatheter and the peritoneal catheter. The system may include first andsecond valves in operable communication with the implantable device, thesecond valve being configured to be actuated so as to prevent flow fromthe bladder to the peritoneum when the fluid is pumped from thereservoir to the peritoneum, the first valve being configured to beactuated so as to prevent flow from the peritoneum to the reservoir whenthe fluid is pumped from the peritoneum to the bladder.

The charging and communication system may further include a handpiecehousing the second controller, the second transceiver, the secondinductive charging circuit and a second battery; and a base containingcircuitry for charging the second battery. The second inductive circuitmay include a coil, and the handpiece may be configured to facilitateexternally positioning the handpiece in alignment with the implantabledevice.

The first controller may be programmed to automatically activate themotor and gear pump to move fluid during predetermined time periods andin predetermined volumes responsive to operational parameterscommunicated by the monitoring and control software. The firstcontroller may be programmed to automatically activate the motor andgear pump to move fluid at high flow rates during pumping, and therebyclean the inflow and outflow catheters to reduce the risk of clogging.The first controller may be programmed to periodically activate themotor and gear pump in a tick mode to reduce potential clogging,substantially without moving fluid through the outflow catheter. Thefirst controller may be programmed to operate the motor and gear pump ina jog mode to unblock the gear pump, wherein the motor is rapidlyalternated between forward and reverse directions.

The implantable device further may include sensors configured to measurerespiratory rate, fluid temperature, fluid viscosity, fluid pressure inthe peritoneum, and fluid pressure in the bladder, and may be configuredto store data corresponding to measurements made by the sensors. Thecharging and communication system may be configured to wirelesslydownload the data stored on the implantable device to a memory disposedwithin the charging and communication system via the first and secondtransceivers. The monitoring and control software may be configured toperiodically communicate with the charging and communication system,using either a wired or wireless connection, to retrieve the data storedin the memory. The monitoring and control software further may beconfigured to detect a change in the patient's health based on anincrease in at least one of the measured respiratory rate, fluidtemperature, or fluid viscosity above a predefined threshold, and tovisually display to a user information about the detected change in thepatient's health. The monitoring and control software may be furtherconfigured to modify operational parameters of the implantable devicebased on the detected change in the patient's health. The modifiedoperational parameters may include at least one of: a volume of thefluid, a time period for which the fluid is permitted to remain withinthe patient's peritoneum, and a frequency with which fluid is removedfrom the patient's peritoneum to the bladder. The detected change in thepatient's health may be, for example, an infection.

In some embodiments, the implantable device includes an ultraviolet (UV)lamp, and the first controller is configured to expose the fluid tolight from the UV lamp for a sufficient amount of time to inhibit thegrowth of colonies of one or more pathogens.

V. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of selected components of an exemplarysystem constructed in accordance with a first embodiment of the presentinvention.

FIG. 1B is a plan view of selected components of the system of FIG. 1Aas implanted in a patient.

FIG. 1C is a plan view of selected components of an alternative systemas implanted in a patient.

FIG. 1D is a perspective view of a belt that may be used with thesystems of FIG. 1B or 1C.

FIG. 1E is a plan view of selected components of another alternativesystem as implanted in a patient.

FIG. 1F illustrates steps in an exemplary method of using the systems ofFIGS. 1A-1E.

FIGS. 2A and 2B are, respectively, side view and perspective detailedviews of an exemplary embodiment of a peritoneal catheter suitable foruse with the system of the present invention, in which FIG. 2Bcorresponds to detail region 2B of FIG. 2A.

FIGS. 3A and 3B are, respectively, side and perspective views,respectively, of first and second embodiments of bladder catheterssuitable for use with the system of the present invention.

FIG. 4 is a schematic diagram of the electronic components of anexemplary embodiment of the implantable device of the present invention.

FIGS. 5A and 5B are, respectively, a perspective view of the implantabledevice of the present invention with the housing shown in outline and aperspective view of the obverse side of the implantable device with thehousing and low water permeable filler removed.

FIGS. 6A, 6B, 6C and 6D are, respectively, an exploded perspective viewof the drive assembly of the implantable device; front and plan views ofthe upper housing; and a perspective view of the manifold of anexemplary embodiment of the implantable device.

FIGS. 7A and 7B are, respectively, a plan view of the gear pump housingof the implantable device of FIG. 5A, and a plan view of a model of thegear pump constructed in accordance with the principles of the presentinvention.

FIGS. 8A and 8B are, respectively, perspective and top views of thehandpiece portion of an exemplary charging and communication system ofthe present invention;

FIG. 9 is a schematic diagram of the electronic components of anexemplary embodiment of the charging and communication system of thepresent invention.

FIG. 10 is a schematic diagram of the functional components of themonitoring and control software employed in an exemplary embodiment ofthe system of the present invention.

FIGS. 11-15 are exemplary screenshots illustrating various aspects ofthe user interface of the monitoring and control system of the presentinvention.

VI. DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention provide systems and methods whereproducts diffuse out of the body via the peritoneal membrane. Thepresent systems and methods pump to the patient's bladder by asubcutaneously implantable pump for evacuation with the urine, ratherthan pumping to an external device. As such, the convenience to thepatient is greatly improved because they need not visit a hospital orother facility to receive a sophisticated extracorporeal process, e.g.,as in U.S. Pat. No. 7,169,303 to Sullivan, and need not wear an externalpump and replaceable cartridge as in U.S. Pat. No. 8,012,118 to Curtin.Additionally, the present systems and methods may also reduce thepatient's blood volume, thus increasing the patient's comfort andreducing the likelihood that the patient will develop one or morecomplications.

As described in greater detail below, preferred embodiments include animplantable device including a pump that is specially configured to movefluid out of the peritoneal cavity and into the bladder, and thatincludes a plurality of sensors for monitoring and recording operatingparameters relevant to the health of the patient. An externally heldcharging and communication system periodically charges and communicateswith the implantable device, and downloads from the device the recordedoperating parameters. Monitoring and control software on the treatingphysician's computer receives the recorded operating parameters from thecharging and communication system, and allows the physician to modifythe operation of the implantable device based on the physician'sperception of the patient's health as reflected in the recordedoperating parameters. Optionally, the monitoring and control softwaremay be configured to alert the physician as to a prediction or detectionof infection based on the recorded operating parameters. The implantabledevice optionally may also include one or more ultraviolet (UV) lampsconfigured to inhibit infection.

System and Method Overview

Referring to FIG. 1A, an overview of selected components of system 10 ofthe present invention is provided. In FIG. 1A, components of the systemare not depicted to scale on either a relative or absolute basis. System10 comprises implantable device 20, external charging and communicationsystem 30, software-based monitoring and control system 40, andreservoir 45. In the illustrated embodiment, monitoring and controlsystem 40 is installed and run on a conventional laptop computer used bythe patient's physician. During patient visits, charging andcommunication system 30 may be coupled, either wirelessly or using acable, to monitoring and control system 40 to download for review datastored on implantable device 20, or to adjust the operational parametersof the implantable device. Monitoring and control system 40 also may beconfigured to upload and store date retrieved from charging andcommunication system 30 to a remote server for later access by thephysician or charging and communications system 30.

Implantable device 20 comprises an electromechanical pump having housing21 configured for subcutaneous implantation. As described in furtherdetail below with reference to FIG. 1B, implantable device 20 mayinclude an electrically-driven mechanical gear pump having inlet port 22coupled to peritoneal catheter 23 and outlet port 24 coupled to bladdercatheter 25, and the fluid is separately provided to the patient'speritoneum from reservoir 45. Peritoneal catheter 23 comprises a tubehaving a first (proximal) end configured to be coupled to pump inlet 23and a second (distal) end configured to be positioned in the peritonealcavity. Bladder catheter 25 comprises a tube having a first (proximal)end configured to be coupled to pump outlet 24 and a second (distal) endconfigured to be inserted through the wall of, and fixed within, apatient's bladder. In a preferred embodiment, both catheters are made ofmedical-grade silicone and include polyester cuffs at their distal ends(not shown) to maintain the catheters in position. Peritoneal catheter23 and bladder catheter 25 are coupled to pump housing 21 usingconnector 26 configured to reduce the risk of improper installation andinadvertent disconnection, and may in addition include distinctcross-sections that reduce the risk of improper installation.

Reservoir 45 is configured to deliver fluid to the patient's peritonealcavity via catheter 46, which may have similar construction to theperitoneal catheter described further below with respect to FIGS. 2A-2B.In embodiments described further below with reference to FIG. 1B, theproximal end of catheter 46 may be configured to be removably coupled toan external reservoir 45 via an appropriate coupling allowing thepatient to easily exchange a depleted reservoir for a fresh one, and thedistal end of catheter 46 may configured for implantation in thepatient's peritoneum, with a tissue cuff (not shown) to promote tissueingrowth at the point at which catheter 46 crosses the patient's skin.The distal end of catheter 46 may have a plurality of holes or aperturesdefined therein, like those discussed below with reference to FIG. 2B.Reservoir 45 may deliver the fluid to the peritoneal cavity by anysuitable mechanism, For example, an external pump may be used tofacilitate fluid flow from the reservoir 45 to the peritoneum, or thereservoir may be physically raised above the level of the peritoneumsuch that gravity draws the fluid into the peritoneum via catheter 46.In other embodiments described below with reference to FIGS. 1C-1E, thedistal end of reservoir catheter 46 instead may be attached to the inletport 22 of implantable device 20, and implantable device 20 may beconfigured to pump the fluid from reservoir 45 into the peritonealcavity via reservoir catheter 46 and peritoneal catheter 23. In suchembodiments, reservoir 45 may be external or implantable, andimplantable device 45 further may include one or more passive or activevalves to prevent fluid from being pumped out of the bladder and intothe peritoneum at the same time that fluid is pumped from the reservoirand into the peritoneum.

The composition of the dialysate may include, for example, electrolytesand albumin, in sufficient concentrations as to cause sufficientquantities of products to diffuse into the dialysate via the peritonealmembrane. In particular, the albumin preferably is provided at aconcentration sufficient to bind to water insoluble or poorly watersoluble products and thus facilitate their removal from the body via thebladder. Other components of the dialysate may include sodiumbicarbonate, although sodium chloride or sodium lactate may alsosuitably be used, and glucose.

Preferably, implantable device 20 is configured to move fluid from theperitoneum to the bladder in quantities and intervals selected toprovide sufficient time for a sufficient amount of products to diffuseinto the fluid to maintain or improve the health of the patient. Forexample, relatively large quantities (e.g., 1-2.5 liters) may be movedin relatively long intervals (e.g., every 4-8 hours). In otherembodiments, implantable device 20 may be configured to move fluid fromthe peritoneum to the bladder in short (e.g., 10 second) intervals(e.g., every 10-20 minutes). Such short but frequent intervals areexpected to inhibit the accumulation of material on the interior lumensof catheters 23 and 25, and reducing the risk for tissue ingrowth. Thefluid circuit of implantable device 20 may be configured to provide anaverage flow rate of about 1-2.5 liters/hour, although much higher andlower flow rates are possible if needed. As described in detail below,the pumping time and volume, including maximum and minimum limits fordaily pumped volume and the time allowed to remain in the peritonealcavity, may be programmed by the physician using monitoring and controlsystem 40 as required for a specific patient.

Additionally, as further described below, implantable device 20 includespressure sensors that monitor pressure in both the peritoneal cavity andthe bladder, such that pumping of fluid into the bladder is disableduntil the bladder is determined to have sufficient space to accommodateadditional fluid. For patient comfort, implantable device 10 optionallymay be programmed not to pump at night or when an accelerometer includedin the implantable device indicates that the patient is asleep (and thusunlikely to be able to void the bladder). Implantable device 20preferably includes multiple separate fail-safe mechanisms, to ensurethat urine cannot pass from the bladder to the peritoneal cavity throughthe pump, thereby reducing the risk of transmitting infection.

Still referring to FIG. 1A, external charging and communication system30 in a preferred form comprises base 31 and handpiece 32. In thisembodiment, handpiece 32 contains a controller, a radio transceiver, aninductive charging circuit, a battery, a quality-of-charging indicatorand a display, and is removably coupled to base 31 to recharge itsbattery. Base 31 may contain a transformer and circuitry for convertingconventional 120V power service to a suitable DC current to chargehandpiece 32 when coupled to base 31. In alternative embodiments,handpiece 32 may include such circuitry and a detachable power cord,thereby permitting the handpiece to be directly plugged into aconvention 120V wall socket to charge the battery. In a preferredembodiment, each of implantable device 20 and handpiece 32 includes adevice identifier stored in memory, such that handpiece 32 provided tothe patient is coded to operate only with that patient's specificimplantable device 20.

Handpiece 32 preferably includes housing 33 having multi-function button34, display 35, a plurality of light emitting diodes (LEDs, not shown)and inductive coil portion 36. Multi-function button 34 provides thepatient the ability to issue a limited number of commands to implantabledevice 20, while display 35 provides visible confirmation that a desiredcommand has been input; it also displays battery status. Inductive coilportion 36 houses an inductive coil that is used transfer energy fromhandpiece 32 to recharge the battery of implantable device 20. The LEDs,which are visible through the material of housing 33 when lit, may bearranged in three rows of two LEDs each, and are coupled to the controlcircuitry and inductive charging circuit contained within handpiece 32.As described in further detail below, the LEDs may be arranged to lightup to reflect the degree of inductive coupling achieved betweenhandpiece 32 and implantable device 20 during recharging of the latter.Alternatively, the LEDs may be omitted and an analog display provided ondisplay 35 indicating the quality of inductive coupling.

As further described in detail below, the control circuitry containedwithin handpiece 32 is coupled to the inductive charging circuit,battery, LEDs and radio transceiver, and includes memory for storinginformation from implantable device 20. Handpiece 32 also preferablyincludes a data port, such as a USB port, that permits the handpiece tobe coupled to monitoring and control system 40 during visits by thepatient to the physician's office. Alternatively, handpiece 32 mayinclude a wireless chip, e.g., conforming to the BLUETOOTH™ or IEEE802.11 wireless standards, thereby enabling the handpiece to communicatewirelessly with monitoring and control system 40, either directly or viathe Internet.

Monitoring and control system 40 is intended primarily for use by thephysician and comprises software configured to run on a conventionalcomputer, e.g., a laptop as illustrated in FIG. 1A. The software enablesthe physician to configure, monitor and control operation of chargingand communication system 30 and implantable device 20. As described indetail below, the software may include routines for configuring andcontrolling pump operation, such as a target amount of fluid to movedaily or per motor actuation, intervals between pump actuation, andlimits on peritoneal cavity pressure, bladder pressure, pump pressure,and battery temperature. System 40 also may provide instructions toimplantable device 20 via charging and control system 30 to controloperation of implantable device 20 so as not to move fluid duringspecific periods (e.g., at night) or to defer pump actuation if thepatient is asleep. System 40 further may be configured, for example, tosend immediate commands to the implantable device to start or stop thepump, or to operate the pump in reverse or at high power to unblock thepump or associated catheters. The software of system 40 also may beconfigured to download real-time data relating to pump operation, aswell as event logs stored during operation of implantable device 20.Based on the downloaded data, e.g., based on measurements made of thepatient's temperature, respiratory rate, and/or fluid viscosity, thesoftware of system 40 optionally may be configured to alert thephysician to a prediction or detection of infection and/or a change inthe patient's health for which an adjustment to the flow rate, volume,time and/or frequency of pump operation may be required. Finally, system40 optionally may be configured to remotely receive raw or filteredoperational data from a patient's handpiece 32 over a secure Internetchannel.

Turning now to FIGS. 1B-1E, plan views of various possibleconfigurations of implantable device 20 and reservoir 45, as implantedin a patient, will now be described. Methods of using system 10,including device 20 and reservoir 45 implanted as illustrated in FIGS.1B-1E, to treat a patient will be provided further below with referenceto FIG. 1F.

Specifically, FIG. 1B illustrates an embodiment in which implantabledevice 20 is implanted subcutaneously, preferably outside of thepatient's peritoneum 11 as defined by peritoneal membrane 12 but beneaththe subject's skin 14 so that it may readily be charged by, andcommunicate with, charging and communication system 30 illustrated inFIG. 1A. Device 20 is coupled via appropriate connectors (not shown) toperitoneal catheter 23 and bladder catheter 25. Peritoneal catheter 23is configured for implantation in the patient's peritoneum 11 andpreferably includes apertures 53 such as described in further detailbelow with reference to FIGS. 2A-2B. Bladder catheter 25 is configuredfor implantation in the patient's bladder 13 and preferably includes ananchor to secure the outlet end of the catheter within the bladder 13,such as described in further detail below with reference to FIGS. 3A-3B.

As illustrated in FIG. 1B, reservoir 45 is positioned outside of thebody and fluidically coupled to the peritoneal cavity via catheter 46.Catheter 46 is coupled to reservoir 45 via connector 47, which isconfigured so as to allow the patient to periodically replace reservoir45 with ease. Catheter 46 preferably includes apertures 53′, which maybe similar in dimension and density to apertures 53, and which allowflow into the peritoneum 11 in a relatively diffuse manner. In theillustrated embodiment, external pump 48 is configured to cause flowfrom reservoir 45 into the peritoneum 11 at a desired rate. For example,reservoir 45 may be positioned on belt 57 which is described furtherbelow with respect to FIG. 1D and which includes pump 48. Pump 48 may beconfigured to communicate wirelessly with implantable device 20 so as tocoordinate delivery into the patient's peritoneum. In an alternativeembodiment, reservoir 45 is positioned at a level above the peritoneum11 such that gravity causes flow from reservoir 45 into the peritoneumat a desired rate. In either embodiment, reservoir 45 preferablyprovides fluid to the peritoneum 11 in a volume, at a rate, and with afrequency suitable to sufficiently fill the peritoneum to allow asufficient amount of products to diffuse to maintain or improve thehealth of the patient. Such volume, rate, and frequency may beapproximately the same as the volume, rate, and frequency with whichimplantable device 20 removes products from the peritoneal cavity to thepatient's bladder 13.

Alternatively, as illustrated in FIG. 1C, reservoir 45 may be positionedoutside of the patient's body, e.g., using belt 57 described furtherbelow with reference to FIG. 1D, and may be coupled to implantabledevice 20 via catheter 46′ and connector 47. Implantable device 20 isconfigured to pump into peritoneum 11 from reservoir 45 via catheters46′ and 23, and then at a later time to pump from peritoneum 11 intobladder 13 via catheters 23 and 25. Specifically, the inlet 22 ofimplantable device 20 comprises a first valve 49 to which catheters 23and 46′ are both connected, and the outlet 24 of implantable device 20comprises a second valve 49′ to which catheter 25 is connected. Duringpumping operations, implantable device 20 controls valves 49 and 49′ soas to prevent fluid from being inadvertently pumped from the bladderinto the peritoneal cavity. For example, to pump fluid into theperitoneum 11 from reservoir 45, implantable device 20 may close offfluidic communication to catheter 25 by appropriately actuating valve49′, may open fluidic communication between catheters 46′ and 23 byappropriately actuating valve 49, and may turn in a first direction soas to pump fluid from reservoir 45 via catheters 46′ and 23. Then, afterthe fluid has been in the peritoneum for a predetermined amount of time,implantable device 20 may pump that fluid to the patient's bladder 13 byclosing off fluidic communication to catheter 46′ and opening fluidiccommunication to catheter 23 by appropriately actuating valve 49,opening fluidic communication to catheter 25 by appropriately actuatingvalve 49′, and turning in a second direction (opposite from the first)so as to pump the fluid into bladder 13 via catheters 23 and 25. Itshould be appreciated that the functionalities of valves 49 and 49′ maybe provided by any desired number of valves that are disposedappropriately along catheters 23, 25, and 46′ and are controllablyactuated by implantable device 20, e.g., via valve controller 86illustrated in FIG. 4. In certain configurations, the use of one or morepassive valves (not controlled by implantable device 20) may beappropriate, e.g., valve 49′ may be a passive check valve disposed alongcatheter 25 that inhibits fluid to flow from the bladder to device 20.

FIG. 1D illustrates a belt 57 that may be used to removably securereservoir 45 illustrated in FIGS. 1B and 1C to the patient's body. Belt57 includes pouch(es) 58, flexible band of material 59, fastener 59′,and optional pump 48. Pouch(es) 58 may include one long, continuouspouch that contains the fluid, or alternatively may include a pluralityof pouches interconnected by catheters, and may be coupled to catheter46 or 46′ via connector 47. Preferably, pouch(es) 58 hold a sufficientamount for one day or one treatment cycle, e.g., 1-2.5 liters, and maybe configured for single use and easy replaceability, or may besterilizable and refillable. Pouch(es) 58 may be arranged generallylinearly along the length of the flexible band of material 59, and maybe secured thereto by an appropriate mechanism, e.g., with thin bands ofmaterial secured by snaps, buttons, hook-and-pile fasteners, and thelike. Flexible band of material 59 may be formed of any suitable fabric,including but not limited to a stretchable, form-fitting material thatmay fit unobtrusively under the patient's clothes. Fastener 59′ isconfigured to allow the patient to repeatedly wear belt 57, and mayinclude, for example, snap(s), a buckle, a zipper, or a hook-and-pilefastener, as is illustrated.

Optional pump 48 (including a power source such as a battery, not shown)is configured to facilitate flow of into the peritoneum, e.g., asdescribed above with respect to FIG. 1B. Pump 48 may include a wirelesstransceiver that communicates with implantable device 20 to coordinatedelivery from the reservoir to the peritoneum with the removal from theperitoneum to the bladder. Additionally, or alternatively, anultraviolet (UV) source such as described below with respect to FIGS. 4and 5B, and appropriate power source, may be provided on belt 57 andconfigured to irradiate the fluid before it enters, or as it enters,catheter 46 or 46′.

FIG. 1E illustrates an alternative configuration to those of FIGS.1B-1D, in which reservoir 45′ is instead implanted within the patient'sbody, e.g., within the peritoneum 11. Implantable device 20 isconfigured to pump into peritoneum 11 from reservoir 45, and then at alater time to pump from peritoneum 11 into bladder 13, using catheters46, 23, and 25 and valves 49 and 49′ in a manner analogous to thatdescribed above with respect to FIG. 1D. However, instead of positioningreservoir 45 on belt 47, as illustrated in FIG. 1D, or hanging reservoir45 over the level of the peritoneum as described above with reference toFIG. 1B, the embodiment illustrated in FIG. 1E may further improveconvenience the patient by disposing reservoir 45′ within the peritonealcavity and providing port 45″ and port catheter 46′ via which thepatient may periodically fill the reservoir. In one illustrativeembodiment, port 45″ comprises a flexible, self-sealing membrane thatthe patient may pierce with a needle connected to a separate, externalreservoir (not shown) for re-filling internal reservoir 45′.

Methods of using systems such as illustrated in FIGS. 1A-1E will now bedescribed with reference to FIG. 1F.

Method 1000 illustrated in FIG. 1F includes introducing to theperitoneal cavity from a reservoir that is internal or external to thepatient's body (step 1010). For example, as described above withreference to FIGS. 1B and 1D, may be introduced using an external pumpor gravity. Or, as described above with reference to FIGS. 1C and 1E,may be introduced using implantable device 20 and one or more valves incommunication therewith. A sufficient amount is introduced to allow asufficient amount of products to be removed when that is removed fromthe peritoneum.

Products then diffuse, e.g., via the peritoneal membrane, thus reducingthe levels of those products in the patient's blood (step 1020).

Then, is pumped from the peritoneal cavity to the bladder with theimplantable device (step 1030). Such pumping may occur after asufficient amount of time to draw a sufficient amount of products out ofthe body to maintain, or even improve, health.

Energy may be wirelessly transferred to the implantable device, and datareceived from the device, using a charging and communication system suchas described briefly above with reference to FIG. 1A and as described ingreater detail below with reference to FIGS. 8A-9 (step 1040). Forexample, the implantable device may record parameters reflective of thehealth of the patient and the operation of the device, which parametersmay be communicated to the charging and communication system.

The data, e.g., parameters recorded by the implantable device, then isprovided to monitoring and control software, which is in communicationwith the charging and communication system and is under the control ofthe treating physician (step 1050).

Based on those parameters, the health of the patient may be assessedusing the software, and the physician may remotely communicate anymodifications to the flow rate, volume, time duration, or frequency withwhich the implantable device is to maintain in the peritoneal cavitybefore removing it to the bladder (step 1060). Such communication may beperformed via the charging and communication system.

Further details of selected components of the systems and methods ofFIGS. A-1F will now be provided with reference to FIGS. 2A-15.

Peritoneal and Bladder Catheters

Referring to FIGS. 2A and 2B, exemplary peritoneal catheter 50constructed in accordance with the principles of the present inventionis described. Peritoneal catheter 50 corresponds to peritoneal catheter23 described above with reference to FIGS. 1A-1E, and preferablycomprises tube 51 of medical-grade silicone including inlet (distal) end52 having a plurality of through-wall holes 53 and outlet (proximal) end54. Peritoneal catheter preferably has length L1 of about 40 cm, withholes 53 extending over length L2 of about 24 cm from inlet end 52.Holes 53 preferably are arranged circumferentially offset by about 90°and longitudinally offset between about 8 mm to 10 mm, as shown in FIG.2B. In one preferred embodiment, 29 holes 53 are arranged in four rowsof 7 holes each, extend only through one wall of the peritoneal catheterat each location, and have a size of between 2.0 to 2.5 mm. Peritonealcatheter 50 preferably includes solid silicone plug 55 that fills distalend of the lumen for a distance of about 7-10 mm to reduce tissueingrowth, and radiopaque strip 56 disposed on, or embedded within, thecatheter that extends the entire length of the catheter, that rendersthe catheter visible in fluoroscopic or X-ray images. Peritonealcatheter 50 may also include a polyester cuff (not shown) in the regionaway from holes 53, to promote adhesion of the catheter to thesurrounding tissue, thereby anchoring it in place.

Alternatively, inlet end 52 of peritoneal catheter 50 may have a spiralconfiguration, and an atraumatic tip, with holes 53 distributed over alength of the tubing to reduce the risk of clogging. As a furtheralternative, inlet end 52 may include a portion having an enlargeddiameter, as disclosed in U.S. Pat. No. 4,657,530, or a reservoir asdisclosed in FIGS. 9 to 16 of U.S. Patent Application Publication US2009/0318844, the entire contents of both of which are incorporatedherein by reference, to further reduce the risk of clogging. Inlet end52 also may terminate in a duck-bill valve, as shown for example in U.S.Pat. No. 4,240,434, thereby permitting the catheter to be cleaned insitu by disconnecting the outlet end of the catheter from implantabledevice 20 and extending a rod from the outlet end of catheter 50 throughthe duckbill valve at the inlet end.

Inlet end 52 also may include a polyester cuff to promote adhesion ofthe catheter to an adjacent tissue wall, thereby ensuring that the inletend of the catheter remains in position. Outlet end 54 also may includea connector for securing the outlet end of the peritoneal catheter toimplantable device 20. In one preferred embodiment, the distal end ofthe peritoneal catheter, up to the ingrowth cuff, may be configured topass through a conventional 16 F peel-away sheath. In addition, thelength of the peritoneal catheter may be selected to ensure that it laysalong the bottom of the body cavity, and is sufficiently resistant totorsional motion so as not to become twisted or kinked during or afterimplantation.

With respect to FIG. 3A, a first embodiment of bladder catheter 60 ofthe present invention is described, corresponding to bladder catheter 25of FIGS. 1A-1E. Bladder catheter 60 preferably comprises tube 61 ofmedical-grade silicone having inlet (proximal) end 62 and outlet(distal) end 63 including spiral structure 64, and polyester ingrowthcuff 65. Bladder catheter 60 includes a single internal lumen thatextends from inlet end 62 to a single outlet at the tip of spiralstructure 64, commonly referred to as a “pigtail” design. Inlet end 62may include a connector for securing the inlet end of the bladdercatheter to implantable device 20, or may have a length that can betrimmed to fit a particular patient. In one example, bladder catheter 60may have length L3 of about 45 cm, with cuff 65 placed length L4 ofabout 5 to 6 cm from spiral structure 64. Bladder catheter 60 may beloaded onto a stylet with spiral structure 64 straightened, andimplanted using a minimally invasive technique in which outlet end 63and spiral structure 64 are passed through the wall of a patient'sbladder using the stylet. When the stylet is removed, spiral structure64 returns to the coiled shape shown in FIG. 3A. Once outlet end 63 ofbladder catheter 60 is disposed within the patient's bladder, theremainder of the catheter is implanted using a tunneling technique, suchthat inlet end 62 of the catheter may be coupled to implantable device20. Spiral structure 64 may reduce the risk that outlet end 63accidentally will be pulled out of the bladder before the tissuesurrounding the bladder heals sufficiently to incorporate ingrowth cuff65, thereby anchoring the bladder catheter in place.

In a preferred embodiment, bladder catheter 60 is configured to passthrough a conventional peel-away sheath. Bladder catheter 60 preferablyis sufficiently resistant to torsional motion so as not to becometwisted or kinked during or after implantation. In a preferredembodiment, peritoneal catheter 50 and bladder catheter 60 preferablyare different colors, have different exterior shapes (e.g., square andround) or have different connection characteristics so that they cannotbe inadvertently interchanged during connection to implantable device20. Optionally, bladder catheter 60 may include an internal duckbillvalve positioned midway between inlet 62 and outlet end 63 of thecatheter to ensure that urine does not flow from the bladder into theperitoneal cavity if the bladder catheter is accidentally pulled freefrom the pump outlet of implantable device 20 and/or if the pump ofimplantable device 20 is actuated so as to draw fluid from reservoir 45into the patient's peritoneal cavity.

In an alternative embodiment, the peritoneal and bladder cathetersdevices may incorporate one or several anti-infective agents to inhibitthe spread of infection between body cavities. Examples ofanti-infective agents which may be utilized may include, e.g.,bacteriostatic materials, bacteriocidal materials, one or moreantibiotic dispensers, antibiotic eluting materials, and coatings thatprevent bacterial adhesion, and combinations thereof. Additionally,implantable device 20 may include a UV lamp configured to irradiatefluid in the peritoneal and/or bladder catheters so as to kill anypathogens that may be present and thus inhibit the development ofinfection, as described further below with respect to FIGS. 4 and 5B.

Alternatively, rather than comprising separate catheters, peritoneal andbladder catheters 50, 60 may share a common wall, which may beconvenient because the bladder and peritoneal cavity share a commonwall, thereby facilitating insertion of a single dual-lumen tube. Inaddition, either or both of the peritoneal or bladder catheters may bereinforced along a portion of its length or along its entire lengthusing ribbon or wire braiding or lengths of wire or ribbon embedded orintegrated within or along the catheters. The braiding or wire may befabricated from metals such as stainless steels, superelastic metalssuch as nitinol, or from a variety of suitable polymers. Suchreinforcement may also be used for catheter 46 connected to reservoir45.

With respect to FIG. 3B, a second embodiment of an bladder catheter ofthe present invention is described, in which similar components areidentified with like-primed numbers. Bladder catheter 60′ preferablycomprises tube 61′ of medical-grade silicone having inlet end 62′,outlet end 63′ and polyester ingrowth cuff 65′. In accordance with thisembodiment, outlet end 63′ includes malecot structure 66, illustrativelycomprising four resilient wings 67 that expand laterally away from theaxis of the catheter to reduce the risk that outlet end 63′ of thecatheter will be inadvertently pulled loose after placement. Inlet end62′ may include a connector for securing the inlet end of the bladdercatheter to implantable device 20, or may have a length that can betrimmed to fit a particular patient.

Malecot structure 66 preferably is constructed so that wings 67 deformto a substantially flattened configuration when a stylet is insertedthrough the lumen of the catheter. In this manner, bladder catheter 60′may be loaded onto a stylet, and using a minimally invasive technique,outlet end 63′ and malecot structure 66 may be passed through the wallof a patient's bladder using the stylet. When the stylet is removed,wings 67 of the malecot structure return to the expanded shape shown inFIG. 3B. Once outlet end 63′ of bladder catheter 60′ is coupled to thepatient's bladder, the remainder of the catheter is implanted using atunneling technique, such that inlet end 62′ of the catheter may becoupled to implantable device 20. Malecot structure 66 may reduce therisk that outlet end 63′ accidentally will be pulled out of the bladderbefore the tissue surrounding the bladder heals sufficiently toincorporate ingrowth cuff 65′. As for the embodiment of FIG. 3A, thebladder catheter of FIG. 3B may be configured to pass through aconventional peel-away sheath, and preferably is sufficiently resistantto torsional motion so as not to become twisted or kinked during orafter implantation.

The Implantable Device

Referring now to FIG. 4, a schematic depicting the functional blocks ofimplantable device 20 of the present invention is described. Implantabledevice 20 includes control circuitry, illustratively processor 70coupled to nonvolatile memory 71, such as flash memory or electricallyerasable programmable read only memory, and volatile memory 72 via databuses. Processor 70 is electrically coupled to electric motor 73,battery 74, inductive circuit 75, radio transceiver 76, UV lamp 85, anda plurality of sensors, including humidity sensor 77, a plurality oftemperature sensors 78, accelerometer 79, a plurality of pressuresensors 80, and respiratory rate sensor 81. Inductive circuit 75 iselectrically coupled to coil 84 to receive energy transmitted fromcharging and communication system 30, while transceiver 76 is coupled toantenna 82, and likewise is configured to communicate with a transceiverin charging and communication system 30, as described below. Optionally,inductive circuit 75 also may be coupled to infrared light emittingdiode 83. Motor 73 may include a dedicated controller, which interpretsand actuates motor 73 responsive to commands from processor 70.Optionally, processor 70 is further in communication with valvecontroller 86. All of the components depicted in FIG. 4 are containedwithin a low volume sealed biocompatible housing, as shown in FIG. 5A.

Processor 70 executes firmware stored in nonvolatile memory 71 whichcontrols operation of motor 73 responsive to signals generated by motor73, sensors 77-81 and commands received from transceiver 76. Processor70 also controls reception and transmission of messages via transceiver76 and operation of inductive circuit 75 to charge battery 74. Inaddition, processor 70 receives signals generated by Hall Effect sensorslocated within motor 73, which are used to compute direction andrevolutions of the gears of the gear pump, and thus fluid volume pumpedand the viscosity of that fluid, as described below. Processor 70preferably includes a low-power mode of operation and includes aninternal clock, such that the processor can be periodically awakened tohandle pumping, pump tick mode, or communications and chargingfunctions, and/or awakened to handle commands received by transceiver 76from handpiece 32. In one embodiment, processor 70 comprises a member ofthe MSP430 family of microcontroller units available from TexasInstruments, Incorporated, Dallas, Tex., and may incorporate thenonvolatile memory, volatile memory, and radio transceiver componentsdepicted in FIG. 4. In addition, the firmware executed on processor 70may be configured to respond directly to commands sent to implantabledevice 20 via charging and communication system 30. Processor 70 also isconfigured to monitor operation of motor 72 (and any associated motorcontroller) and sensors 77-81, as described below, and to store datareflecting operation of the implantable device, including event logs andalarms. Thus, data is reported to the charging and communication systemwhen it is next wirelessly coupled to the implantable device. In apreferred embodiment, processor 70 generates up to eighty log entriesper second prior to activating the pump, about eight log entries persecond when the implantable system is actively pumping and about one logentry per hour when not pumping.

Nonvolatile memory 71 preferably comprises flash memory or EEPROM, andstores a unique device identifier for implantable device 20, firmware tobe executed on processor 70, configuration set point data relating tooperation of the implantable device, and optionally, coding to beexecuted on transceiver 76 and/or inductive circuit 75, and a separatemotor controller, if present. Firmware and set point data stored onnonvolatile memory 71 may be updated using new instructions provided bycontrol and monitoring system 40 via charging and communication system30. Volatile memory 72 is coupled to and supports operation of processor70, and stores data and event log information gathered during operationof implantable device 20. Volatile memory 72 also serves as a buffer forcommunications sent to, and received from, charging and communicationsystem 30.

Transceiver 76 preferably comprises a radio frequency transceiver and isconfigured for bi-directional communications via antenna 76 with asimilar transceiver circuit disposed in handpiece 32 of charging andcommunication system 30. Transceiver 76 also may include a low powermode of operation, such that it periodically awakens to listen forincoming messages and responds only to those messages including theunique device identifier assigned to that implantable device.Alternatively, because transceiver 76 communicates only with thecorresponding transceiver in handpiece 32 of its associated charging andcommunication system 30, transceiver 76 may be configured to send orreceive data only when inductive circuit 75 of the implantable device isactive. In addition, transceiver 76 may employ an encryption routine toensure that messages sent from, or received by, the implantable devicecannot be intercepted or forged.

Inductive circuit 75 is coupled to coil 84, and is configured torecharge battery 74 of the implantable device when exposed to a magneticfield supplied by a corresponding inductive circuit within handpiece 32of charging and communication system 30. In one embodiment, inductivecircuit 75 is coupled to optional infrared LED 83 that emits an infraredsignal when inductive circuit 75 is active. The infrared signal may bereceived by handpiece 32 of charging and communication system 30 toassist in locating the handpiece relative to the implantable device,thereby improving the magnetic coupling and energy transmission to theimplantable device.

In accordance with one aspect of the present invention, inductivecircuit 75 optionally may be configured not only to recharge battery 74,but to directly provide energy to motor 73 in a “boost” mode orjog/shake mode to unblock the pump. In particular, if processor 70detects that motor 73 is stalled, e.g., due to a block created byproteins in the fluid, an alarm may be stored in memory. Whenimplantable device 20 next communicates with charging and communicationsystem 30, the alarm is reported to handpiece 32, and the patient may begiven the option of depressing multifunction button 34 to apply anovervoltage to motor 73 from inductive circuit 75 for a predeterminedtime period to free the pump blockage. Alternatively, depressing themulti-function button may cause processor 70 to execute a set ofcommands by which motor 73 is jogged or shaken, e.g., by alternatinglyrunning the motor is reverse and then forward, to disrupt the blockage.Because such modes of operation may employ higher energy consumptionthan expected during normal operation, it is advantageous to drive themotor during such procedures with energy supplied via inductive circuit75.

Battery 74 preferably comprises a lithium ion or lithium polymer batterycapable of long lasting operation, e.g., up to three years, whenimplanted in a human, so as to minimize the need for re-operations toreplace implantable device 20. In one preferred embodiment, battery 74supplies a nominal voltage of 3.6V, a capacity of 150 mAh when new, anda capacity of about 120 mAh after two years of use. Preferably, battery74 is configured to supply a current of 280 mA to motor 73 when pumping;25 mA when the transceiver is communicating with charging andcommunication system 30; 8 mA when processor 70 and related circuitry isactive, but not pumping or communicating; and 0.3 mA when theimplantable device is in low power mode. More preferably, battery 74should be sized to permit a minimum current of at least 450 mAh for aperiod of 10 seconds and 1 A for 25 milliseconds during each chargingcycle.

Motor 73 preferably is a brushless direct current or electronicallycommuted motor having a splined output shaft that drives a set offloating gears that operate as a gear pump, as described below. Motor 73may include a dedicated motor controller, separate from processor 70,for controlling operation of the motor. Motor 73 may include a pluralityof Hall Effect sensors, preferably two or more, for determining motorposition and direction of rotation. Due to the high humidity that may beencountered in implantable device 20, processor 70 may includeprogramming to operate motor 73, although with reduced accuracy, even ifsome or all of the Hall Effect sensors fail.

In a preferred embodiment, motor 73 is capable of driving the gear pumpto generate a nominal flow rate of 150 ml/min and applying a torque ofabout 1 mNm against a pressure head of 30 cm water at 3000 RPM. In thisembodiment, the motor preferably is selected to drive the gears at from1000 to 5000 RPM, corresponding to flow rates of from 50 to 260 ml/min,respectively. The motor preferably has a stall torque of at least 3 mNmat 500 mA at 3 V, and more preferably 6 mNm in order to crush non-solidproteinaceous materials. As discussed above, the motor preferably alsosupports a boost mode of operation, e.g., at 5 V, when powered directlythrough inductive circuit 75. Motor 73 preferably also is capable ofbeing driven in reverse as part of a jogging or shaking procedure tounblock the gear pump.

In accordance with one aspect of the present invention, processor 70 maybe programmed to automatically and periodically wake up and enter a pumptick mode. In this mode of operation, the gear pump is advancedslightly, e.g., about 120° as measured by the Hall Effect sensors,before processor 70 returns to low power mode. Preferably, this intervalis about every 20 minutes, although it may be adjusted by the physicianusing the monitoring and control system. This pump tick mode is expectedto prevent the fluid, which may have a high protein content, frompartially solidifying, and blocking the gear pump.

In addition, processor 70 also may be programmed to enter a jog or shakemode when operating on battery power alone, to unblock the gear pump.Similar to the boost mode available when charging the implantable devicewith the handpiece of charging and communication system 30, the jog orshake mode causes the motor to rapidly alternate the gears betweenforward and reverse directions to crush or loosen buildup in the gearpump or elsewhere in the fluid path. Specifically, in this mode ofoperation, if the motor does not start to turn within a certain timeperiod after it is energized (e.g., 1 second), the direction of themotion is reversed for a short period of time and then reversed again tolet the motor turn in the desired direction. If the motor does still notturn (e.g., because the gear pump is jammed) the direction is againreversed for a period of time (e.g., another 10 msec). If the motorstill is not able to advance the time interval between reversals of themotor direction is reduced to allow for the motor to develop more power,resulting in a shaking motion of the gears. If the motor does not turnforward for more than 4 seconds, the jog mode of operation is stopped,and an alarm is written to the event log. If the motor was unable toturn forward, processor 70 will introduce a backwards tick before thenext scheduled fluid movement. A backward tick is the same as a tick(e.g., about 120° forward movement of the motor shaft) but in thereverse direction, and is intended to force the motor backwards beforeturning forward, which should allow the motor to gain momentum.

Sensors 77-81 continually monitor humidity, temperature, acceleration,pressure, and respiratory rate, and provide corresponding signals toprocessor 70 which stores the corresponding data in memory 71 for latertransmission to monitoring and control system 40. In particular,humidity sensor 77 is arranged to measure humidity within the housing ofthe implantable device, to ensure that the components of implantabledevice are operated within expected operational limits. Humidity sensor77 preferably is capable of sensing and reporting humidity within arange or 20% to 100% with high accuracy. One or more of temperaturesensors 78 may be disposed within the housing and monitor thetemperature of the implantable device, and in particular battery 74 toensure that the battery does not overheat during charging, while anotherone or more of temperature sensors 78 may be disposed so as to contactfluid entering at inlet 62 and thus monitor the temperature of thefluid, e.g., for use in assessing the patient's health. Accelerometer 79is arranged to measure acceleration of the implant, preferably along atleast two axes, to detect periods of inactivity, e.g., to determinewhether the patient is sleeping. This information is provided toprocessor 70 to ensure that the pump is not operated when the patient isindisposed to attend to voiding of the bladder.

Implantable device 20 preferably includes multiple pressure sensors 80,which are continually monitored during waking periods of the processor.As described below with respect to FIG. 6A, the implantable device ofthe present invention preferably includes four pressure sensors: asensor to measure the pressure in the peritoneal cavity, a sensor tomeasure the ambient pressure, a sensor to measure the pressure at theoutlet of the gear pump, and a sensor to measure the pressure in thebladder. These sensors preferably are configured to measure absolutepressure between 450 mBar and 1300 mBar while consuming less than 50 mWat 3V. Preferably, the sensors that measure pressure at the pump outletand in the bladder are placed across a duckbill valve, which preventsreverse flow of urine back into the gear pump and also permitscomputation of flow rate based on the pressure drop across the duckbillvalve.

Respiratory rate monitor 81 is configured to measure the patient'srespiratory rate, e.g., for use in assessing the patient's health.Alternatively, the patient's respiratory rate may be measured based onthe outputs of one or more of pressure sensors 80, e.g., based onchanges in the ambient pressure or the pressure in the peritoneal cavitycaused by the diaphragm periodically compressing that cavity duringbreathing.

Note that any desired number of additional sensors for measuring thehealth of the patient may also be provided in operable communicationwith processor 70 and may output recordable parameters for storage inmemory 71 and transmission to monitoring and control system 40, that thephysician may use to assess the patient's health. For example, chemicalor biochemical sensors may be provided that are configured to monitorthe levels of one or more products in the fluid.

In preferred embodiments, processor 70 is programmed to pump apredetermined volume of fluid from the peritoneal cavity to the bladderafter that fluid has been in the peritoneal cavity for a predeterminedamount of time and with a predetermined frequency. Such volume, time,and frequency preferably are sufficient for a sufficient amount ofproducts to diffuse into the fluid via the peritoneal membrane tomaintain or improve the health of the patient. The volume, time, andfrequency may be selected upon the health of the patient, the activityand habits of the patient, the permeability of the peritoneal membraneto the products, and the osmotic characteristics. For example, thephysician may initially program processor 70 with a first time, volume,and frequency based on his perception of the patient's health andhabits, and later may adjust that initial programming to vary thevolume, time, and/or frequency based on his perception of changes in thepatient's health, for example based on changes over time in parametersmeasured by implantable device 20 and relayed to the physician viamonitoring and control software 40.

In other embodiments, processor 70 is programmed to pump fluid from theperitoneal cavity to the bladder only when the pressure in theperitoneum exceeds a first predetermined value, and the pressure in thebladder is less than a second predetermined value, so that the bladderdoes not become overfull. To account for patient travel from a locationat sea level to a higher altitude, the ambient pressure measurement maybe used to calculate a differential value for the peritoneal pressure.In this way, the predetermined pressure at which the pump beginsoperation may be reduced, to account for lower atmospheric pressure.Likewise, the ambient pressure may be used to adjust the predeterminedvalue for bladder pressure. In this way, the threshold pressure at whichthe pumping ceases may be reduced, because the patient may experiencebladder discomfort at a lower pressure when at a high altitude location.

Optionally, controller 70 is in operable communication with UV lamp 85,which is configured to irradiate and thus kill pathogens in the fluidboth before and after that fluid is provided to the peritoneal cavity.UV lamp 85 preferably generates light in the UV-C spectral range (about200-280 nm), particularly in the range of about 250-265 nm, which isalso referred to as the “germicidal spectrum” because light in thatspectral range breaks down nucleic acids in the DNA of microorganisms.Low-pressure mercury lamps have an emission peak at approximately 253.7nm, and may suitably be used for UV lamp 85. Alternatively, UV lamp 85may be a UV light emitting diode (LED), which may be based on AlGaAs orGaN.

Under the control of controller 70, UV lamp 85 irradiates any fluid thatenters the implantable device for a preselected amount of timesufficient to kill pathogens that may be present in that fluid.Specifically, the flow rate of the fluid through the device may beselected (e.g., pre-programmed) so as to irradiate the fluid with asufficient dosage of UV light to inhibit the growth of colonies ofpathogens. For example, it is known that dosages of 253.7 nm UV light ofbetween about 5,500-7,000 μWs/cm² are sufficient to provide 100% killrates for many organisms, including E. coli, Proteus spp., Klebsiellaspp., Serratia spp., Leptospirosis spp., Staphylococcus haemolyticus,and Enterococci. Higher dosages, e.g., between about 8,500-12,000μWs/cm², may be required to provide 100% kill rates for other organisms,including Kliebsiella ssp., Enterobacter spp., Psuedomonas spp., andNeisseria gonorrhoeae. However, the dosage to sufficiently inhibitcolony growth may be lower. For example, E. coli requires only 3000μWs/cm² to inhibit growth, whereas 6,600 μWs/cm² may be needed toprovide a 100% kill rate. Controller 70 may be pre-programmed to set aflow rate of fluid through the tubing sufficient to inhibit colonygrowth of one or more target pathogens based on the intensity of UV lamp85, the reflective conditions within the portion of the housing in whichUV lamp 85 is used (e.g., upper portion 93 described below withreference to FIG. 5B), the configuration of the tubing being exposed tothe UV lamp, the distance between the tubing and the UV lamp, and thesusceptibility of target pathogens to the spectrum emitted by UV lamp85.

Still referring to FIG. 4, in some embodiments processor 70 also may bein communication with valve controller 86; alternatively, valvecontroller 86 may be part of the functionality of processor 70. Valvecontroller 86 controls the actuation of any valves that may be used tocontrol the flow of fluid between the reservoir, the peritoneum, and thebladder. For example, as described above with reference to FIGS. 1C and1E, implantable device 20 may be configured to pump fluid from anexternal or internal reservoir to the peritoneum, while actuating valves49 and 49′ so as to close fluidic access to the bladder and thus avoidinadvertently pumping fluid from the bladder into the peritoneum; andmay be configured to pump fluid from the peritoneum to the bladder,while actuating valves 49 and 49′ so as to close fluidic access to thereservoir and thus avoid inadvertently pumping fluid from the peritoneuminto the reservoir. Valve controller 86 may coordinate the actuation ofvalves 49 and 49′ in such a manner, or in any other appropriate mannerbased on the particular valve configuration.

Referring now to FIGS. 5A and 5B, further details of an exemplaryembodiment of implantable device 90 are provided. In FIG. 5A, housing 91is shown as transparent, although it should of course be understood thathousing 91 comprises opaque biocompatible plastic and/or metal alloymaterials. In FIG. 5B, the implantable device is shown with lowerportion 92 of housing 91 removed from upper housing 93 and without aglass bead/epoxy filler material that is used to prevent moisture fromaccumulating in the device. In FIGS. 5A and 5B, motor 94 is coupled togear pump housing 95, which is described in greater detail with respectto FIGS. 6 and 7. The electronic components discussed above with respectto FIG. 4 are disposed on flexible circuit board substrate 96, whichextends around and is fastened to support member 97. Coil 98(corresponding to coil 84 of FIG. 4) is disposed on flap 99 of thesubstrate and is coupled to the electronic components on flap 100 byflexible cable portion 101. Support member 97 is fastened to upperhousing 93 and provides a cavity that holds battery 102 (correspondingto battery 74 of FIG. 4). Lower portion 92 of housing 91 includes port103 for injecting the glass bead/epoxy mixture after upper portion 93and lower portion 92 of housing 91 are fastened together, to reducespace in the housing in which moisture can accumulate.

Housing 91 also may include features designed to reduce movement of theimplantable pump once implanted within a patient, such as a suture holeto securely anchor the implantable device to the surrounding tissue.Housing 91 may in addition include a polyester ingrowth patch thatfacilitates attachment of the implantable device to the surroundingtissue following subcutaneous implantation.

Additionally, the implantable device optionally may incorporateanti-clogging agents, such enzyme eluting materials that specificallytarget the proteinaceous components, enzyme eluting materials thatspecifically target the proteinaceous and encrustation promotingcomponents of urine, chemical eluting surfaces, coatings that preventadhesion of proteinaceous compounds, and combinations thereof. Suchagents, if provided, may be integrated within or coated upon thesurfaces of the various components of the system.

As illustrated in FIG. 5B, upper housing 93 optionally includes UV lamp85 described further above with respect to FIG. 4. Within upper housing93, the fluid channels 88 for conducting the fluid may extendapproximately linearly, or alternatively may include one or more curvesor bends so as to increase the volume of fluid that may besimultaneously exposed UV lamp 86, and thus allow for an increase in theflow rate. For example, the fluid channels 88 may include an approximatespiral, an approximate sine wave, or an approximate “S” curve so as toincrease the volume of fluid that may be simultaneously exposed to UVlamp 86. Upper housing 93 further may include reflective coating 87,e.g., a white coating such as ZnO or other diffuse or Lambertianreflector, so as to enhance irradiation of the tubing and shield thepatient from potential UV light exposure.

Referring now to FIGS. 6A to 6D, further details of the gear pump andfluid path are described. In FIGS. 6A-6D, like components are identifiedusing the same reference numbers from FIGS. 5A and 5B. FIG. 6A is anexploded view showing assembly of motor 94 with gear pump housing 95 andupper housing 93, as well as the components of the fluid path within theimplantable device. Upper housing 93 preferably comprises a highstrength plastic or metal alloy material that can be molded or machinedto include openings and channels to accommodate inlet nipple 102, outletnipple 103, pressure sensors 104 a-104 d, manifold 105 and screws 106.Nipples 102 and 103 preferably are machined from a high strengthbiocompatible metal alloy, and outlet nipple 103 further includeschannel 107 that accepts elastomeric duckbill valve 108. Outlet nipple103 further includes lateral recess 109 that accepts pressure sensor 104a, which is arranged to measure pressure at the inlet end of the bladdercatheter, corresponding to pressure in the patient's bladder (orperitoneal cavity).

Referring now also to FIGS. 6B and 6C, inlet nipple 102 is disposedwithin opening 110, which forms a channel in upper housing 93 thatincludes opening 111 for pressure sensor 104 b and opening 112 thatcouples to manifold 105. Pressure sensor 104 b is arranged to measurethe pressure at the outlet end of the peritoneal catheter, correspondingto pressure in the peritoneal cavity. Outlet nipple 103, includingduckbill valve 107, is disposed within opening 113 of upper housing 93so that lateral recess 108 is aligned with opening 114 to permit accessto the electrical contacts of pressure sensor 104 a. Opening 113 formschannel 115 that includes opening 116 for pressure sensor 104 c, andopening 117 that couples to manifold 105. Upper housing 93 preferablyfurther includes opening 118 that forms a channel including opening 119for accepting pressure sensor 104 d. Pressure sensor 104 d measuresambient pressure, and the output of this sensor is used to calculatedifferential pressures as described above. Upper housing furtherincludes notch 120 for accepting connector 26 (see FIG. 1A) forretaining the peritoneal and bladder catheters coupled to inlet andoutlet nipples 102 and 103. Upper housing 93 further includes recess 121to accept manifold 105, and peg 122, to which support member 97 (seeFIG. 5B) is connected.

As shown in FIGS. 6A and 6D, manifold 105 preferably comprises a moldedelastomeric component having two separate fluid channels (such channelsdesignated 88 in FIG. 5B) that couple inlet and outlet flow pathsthrough upper housing 93 to the gear pump. The first channel includesinlet 124 and outlet 125, while the second channel includes inlet 126and outlet 127. Inlet 124 couples to opening 112 (see FIG. 6C) of theperitoneal path and outlet 127 couples to opening 117 of the bladderpath. Manifold 105 is configured to improve manufacturability of theimplantable device, by simplifying construction of upper housing 93 andobviating the need to either cast or machine components with complicatednon-linear flow paths. Optional UV lamp 86 and surface 87 (not shown inFIGS. 6A-6D) may be placed in suitable positions within housing 93 andrelative to manifold 105 to sufficiently irradiate the fluid as motor 94pumps the fluid through housing 93.

Referring now to FIGS. 6A, 7A and 7B, motor 94 is coupled to gear pumphousing 95 using mating threads 130, such that splined shaft 131 ofmotor 94 passes through bearing 132. The gear pump of the presentinvention comprises intermeshing gears 133 and 134 enclosed in gear pumphousing 95 by O-ring seal 135 and plate 136. The gear pump isself-priming. Plate 136 includes openings 137 and 138 that mate withoutlet 125 and inlet 126 of manifold 105, respectively. Splined shaft131 of motor 94 extends into opening 139 of gear 133 to provide floatingengagement with that gear. Interaction of the splined shaft with thegears is described below with respect to FIG. 7B.

FIG. 7A depicts the obverse side of gear pump housing 95 of FIG. 6A, andincludes recess 140 that is sized to accept gears 133 and 134, andgroove 141 that accepts O-ring seal 135. Gears 133 and 134 are seatedwithin recess 140 such that splined shaft 131 extends through opening142 and floats within keyed opening 139 of gear 133. Gears 133 and 134are dimensioned so as to sit within recess 140 with a close tolerance(e.g., 0.2 mm) to wall 143 of the recess, but spin as freely as theviscosity of the fluid permits. Openings 137 and 138 of plate 136 (seeFIG. 6A) are positioned over the juncture of gears 133 and 134 (shown indotted line in FIG. 7A) so that rotation of gear 133 in a clockwisedirection (when viewed from above) creates suction that draws fluid intothe gear pump housing through opening 137, and expels fluid throughopening 138. Likewise, if motor 94 drives gear 133 in a counterclockwisedirection (as viewed from above), the gear pump will draw fluid into thegear pump housing through opening 138 and expel it through opening 137,thereby reversing flow.

As depicted in the simplified model of FIG. 7B, gear 134 has no axle,but instead floats freely within its portion of recess 140. Splinedshaft 131 engages keyed opening 139 of gear 133, so that gear 133 floatson splined shaft 131. Advantageously, this arrangement improves pumpefficiency and manufacturability, and reduces power consumption by motor94 by reducing the effects of manufacturing variations and thermaleffects. In particular, slight variations in motor shaft eccentricity orstraightness, resulting from manufacturing tolerances or differentialthermal expansion, will not cause the gear to bind against the interiorof recess 140 or against gear 134. Instead, different portions of thesurfaces of shaft 131 and keyed opening 139 contact one another duringrevolution of shaft 131 to continuously transmit rotational torque togear 133. However, energy-wasting forces resulting from shafteccentricities, variations in manufacturing tolerances or differentialthermal expansion of the components are reduced. In addition, thisfloating arrangement may reduce the risk that particulate matter causesbinding between the gears and wall 143, since the gears may movelaterally to accommodate such particulate matter.

Gears 133 and 134 include intermeshing lobes 144 that positivelydisplace fluid as they engage and disengage, with substantially nobypass flow. In this manner the volume and viscosity of fluidtransported by gears 133 and 134 may computed by tracking the number ofmotor revolutions sensed by the Hall Effect sensors disposed withinmotor 94. As further shown in FIGS. 7A and 7B, recess 140 of gear pumphousing 95 comprises two interconnected, substantially circular, lobes.This arrangement retains gears 133 and 134 in proper relation to wall143 of the recess, as well as relative to one another. In a preferredembodiment, cusps 145, formed where the two lobes intersect, areconfigured to form tangents to radii drawn from the centers of therespective lobes. Advantageously, configuring the cusps in this mannerreduces the potential for gears 133 and 134 to impinge upon wall 143.

The Charging and Communication System

Referring to FIGS. 8A, 8B and 9, charging and communication system 150of the present invention (corresponding to system 30 of FIG. 1A) is nowdescribed in greater detail. In one preferred embodiment, charging andcommunication system 150 comprises handpiece 151 and base 31 (see FIG.1A). Base 31 provides comprises a cradle for recharging handpiece 151,and preferably contains a transformer and circuitry for convertingconventional 120V power service to a suitable DC current to chargehandpiece 151 when it is coupled to the base. Alternatively, handpiece151 may include circuitry for charging the handpiece battery, and adetachable power cord. In this embodiment, handpiece 151 may be directlyplugged into a convention 120V wall socket for charging, and the powercord removed when the handpiece is used to recharge the implantabledevice.

As shown in FIG. 9, handpiece 151 contains controller 152,illustratively the processor of a micro-controller unit coupled tononvolatile memory 153 (e.g., either EEPROM or flash memory), volatilememory 154, radio transceiver 155, inductive circuit 156, battery 157,indicator 158 and display 159. Controller 152, memories 153 and 154, andradio transceiver 155 may be incorporated into a single microcontrollerunit, such as the MPS430 family of microprocessors, available from TexasInstruments Incorporated, Dallas, Tex. Transceiver 155 is coupled toantenna 160 for sending and receiving information to implantable device20. Battery 157 is coupled to connector 161 that removably couples witha connector in base 31 to recharge the battery. Port 162, such as a USBport or comparable wireless circuit, is coupled to controller 152 topermit information to be exchanged between handpiece 151 and themonitoring and control system. Inductive circuit 156 is coupled to coil163. Input device 164, preferably a multi-function button, also iscoupled to controller 152 to enable a patient to input a limited numberof commands. Indicator 158 illustratively comprises a plurality of LEDsthat illuminate to indicate the quality of charge coupling achievedbetween the handpiece and implantable device, and therefore assist inoptimizing the positioning of handpiece 151 relative to the implantabledevice during recharging. In one preferred embodiment, indicator 158 isomitted, and instead a bar indicator provided on display 159 thatindicates the quality-of-charging resulting from the coupling of coils163 and 84.

In a preferred embodiment, handpiece 151 includes a device identifierstored in nonvolatile memory 153 that corresponds to the deviceidentifier stored in nonvolatile memory 71 of the implantable device,such that handpiece 151 will communicate only with its correspondingimplantable device 20. Optionally, a configurable handpiece for use in aphysician's office may include the ability to interrogate an implantabledevice to request that device's unique device identifier, and thenchange the device identifier of the monitoring and control system 40 tothat of the patient's implantable device, so as to mimic the patient'shandpiece. In this way, a physician may adjust the configuration of theimplantable device if the patient forgets to bring his handpiece 151with him during a visit to the physician's office.

Controller 152 executes firmware stored in nonvolatile memory 153 thatcontrols communications and charging of the implantable device.Controller 152 also is configured to transfer and store data, such asevent logs, uploaded to handpiece 151 from the implantable device, forlater retransmission to monitoring and control system 40 via port 162,during physician office visits. Alternatively, handpiece 151 may beconfigured to recognize a designated wireless access point within thephysician's office, and to wirelessly communicate with monitoring andcontrol system 40 during office visits. As a further alternative, base31 may include telephone circuitry for automatically dialing anduploading information stored on handpiece 151 to a physician's websitevia a secure connection, such as alarm information.

Controller 152 preferably includes a low-power mode of operation andincludes an internal clock, such that the controller periodicallyawakens to communicate with the implantable device to log data or toperform charging functions. Controller 152 preferably is configured toawaken when placed in proximity to the implantable device to performcommunications and charging functions, and to transmit commands inputusing input device 164. Controller 152 further may include programmingfor evaluating information received from the implantable device, andgenerating an alarm message on display 159. Controller 152 also mayinclude firmware for transmitting commands input using input device 164to the implantable device, and monitoring operation of the implantabledevice during execution of such commands, for example, during boost orjogging/shaking operation of the gear pump to clear a blockage. Inaddition, controller 152 controls and monitors various power operationsof handpiece 151, including operation of inductive circuit 156 duringrecharging of the implantable device, displaying the state of charge ofbattery 74, and controlling charging and display of state of chargeinformation for battery 157.

Nonvolatile memory 153 preferably comprises flash memory or EEPROM, andstores the unique device identifier for its associated implantabledevice, firmware to be executed by controller 152, configuration setpoint, and optionally, coding to be executed on transceiver 155 and/orinductive circuit 156. Firmware and set point data stored on nonvolatilememory 153 may be updated using information supplied by control andmonitoring system 40 via port 162. Volatile memory 154 is coupled to andsupports operation of controller 152, and stores data and event loginformation uploaded from implantable device 20.

In addition, in a preferred embodiment, nonvolatile memory 153 storesprogramming that enables the charging and communication system toperform some initial start-up functions without communicating with themonitor and control system. In particular, memory 153 may includeroutines that make it possible to test the implantable device duringimplantation using the charging and communication system alone in a“self-prime mode” of operation. In this case, a button may be providedthat allows the physician to manually start the pump, and display 159 isused to provide feedback whether the pumping session was successful ornot. Display 159 of the charging and communication system also may beused to display error messages designed to assist the physician inadjusting the position of the implantable device or peritoneal orbladder catheters. These functions preferably are disabled after theinitial implantation of the implantable device.

Transceiver 155 preferably comprises a radio frequency transceiver,e.g., conforming to the BLUETOOTH™ or IEEE 802.11 wireless standards,and is configured for bi-directional communications via antenna 160 withtransceiver circuit 76 disposed in the implantable device. Transceiver155 also may include a low power mode of operation, such that itperiodically awakens to listen for incoming messages and responds onlyto those messages including the unique device identifier assigned to itsassociated implantable device. Transceiver 155 preferably employs anencryption routine to ensure that messages sent to, or received from,the implantable device cannot be intercepted or forged.

Inductive circuit 156 is coupled to coil 163, and is configured toinductively couple with coil 84 of the implantable device to rechargebattery 74 of the implantable device. In one embodiment, inductivecircuit 156 is coupled to indicator 158, preferably a plurality of LEDsthat light to indicate the extent of magnetic coupling between coils 163and 84 (and thus quality of charging), thereby assisting in positioninghandpiece 151 relative to the implantable device. In one preferredembodiment, inductive coils 84 and 163 are capable of establishing goodcoupling through a gap of 35 mm, when operating at a frequency of 315kHz or less. In an embodiment in which implantable device includesoptional infrared LED 83, charging and communication system 30 mayinclude an optional infrared sensor (not shown) which detects thatinfrared light emitted by LED 83 and further assists in positioninghandpiece 151 to optimize magnetic coupling between coils 163 and 84,thereby improving the energy transmission to the implantable device.

In accordance with one aspect of the present invention, controller 152may be configured to periodically communicate with the implantabledevice to retrieve temperature data generated by temperature sensor 78and stored in memory 72 during inductive charging of battery 74.Controller 152 may include firmware to analyze the battery temperature,and to adjust the charging power supplied to inductive circuit 163 tomaintain the temperature of the implantable device below a predeterminedthreshold, e.g., less than 2° C. above body temperature. That thresholdmay be set to reduce thermal expansion of the battery and surroundingelectronic and mechanical components, for example, to reduce thermalexpansion of motor and gear pump components and to reduce the thermalstrain applied to the seal between lower portion 92 of housing and upperhousing 93. In a preferred embodiment, power supplied to inductive coil163 is cycled between high power (e.g., 120 mA) and low power (e.g., 40mA) charging intervals responsive to the measured temperature within theimplantable device.

As discussed above with respect to inductive circuit 75 of theimplantable device, inductive circuit 156 optionally may be configuredto transfer additional power to motor 73 of the implantable device, viainductive circuit 75 and battery 74, in a “boost” mode or jogging modeto unblock the gear pump. In particular, if an alarm is transmitted tocontroller 152 that motor 73 is stalled, e.g., due to a block created byfluid, the patient may be given the option of using input device 164 toapply an overvoltage to motor 73 from inductive circuit 75 for apredetermined time period to free the blockage. Alternatively,activating input device 164 may cause controller 152 to commandprocessor 70 to execute a routine to jog or shake the gear pump byrapidly operating motor 74 in reverse and forward directions to disruptthe blockage. Because such modes of operation may employ higher energyconsumption than expected during normal operation, inductive circuits156 and 75 may be configured to supply the additional energy for suchmotor operation directly from the energy stored in battery 157, insteadof depleting battery 74 of the implantable device.

Battery 157 preferably comprises a lithium ion or lithium polymerbattery capable of long lasting operation, e.g., up to three years.Battery 157 has sufficient capacity to supply power to handpiece 151 tooperate controller 152, transceiver 155, inductive circuit 156 and theassociated electronics while disconnected from base 31 and duringcharging of the implantable device. In a preferred embodiment, battery157 has sufficient capacity to fully recharge battery 74 of theimplantable device from a depleted state in a period of about 2-4 hours.Battery 157 also should be capable of recharging within about 2-4 hours.It is expected that for daily operation moving 700 ml of fluid, battery157 and inductive circuit 156 should be able to transfer sufficientcharge to battery 74 via inductive circuit 75 to recharge the batterywithin about 30 minutes. Battery capacity preferably is supervised bycontroller 152 using a charge accumulator algorithm.

Referring again to FIGS. 8A and 8B, handpiece 151 preferably includeshousing 165 having multi-function button 166 (corresponding to inputdevice 164 of FIG. 9) and display 167 (corresponding to display 159 ofFIG. 9). Plurality of LEDs 168 is disposed beneath a translucent portionof handpiece 151, and corresponds to indicator 158 of FIG. 9. Port 169enables the handpiece to be coupled to monitoring and control system 40(and corresponds to port 162 of FIG. 9), while connector 170(corresponding to connector 161 in FIG. 9) permits the handpiece to becoupled to base 31 to recharge battery 157. Multi-function button 166provides the patient the ability to input a limited number of commandsto the implantable device. Display 167, preferably an OLED or LCDdisplay, provides visible confirmation that a desired command inputusing multifunction button 166 has been received. Display 167 also maydisplay the status and state of charge of battery 74 of the implantabledevice, the status and state of charge of battery 157 of handpiece 151,signal strength of wireless communications, quality-of-charging, errorand maintenance messages. Inductive coil portion 171 of housing 165houses inductive coil 163.

LEDs 168 are visible through the material of housing 165 when lit, andpreferably are arranged in three rows of two LEDs each. During charging,the LEDs light up to display the degree of magnetic coupling betweeninductive coils 163 and 84, e.g., as determined by energy loss frominductive circuit 156, and may be used by the patient to accuratelyposition handpiece 151 relative to the implantable device. Thus, forexample, a low degree of coupling may correspond to lighting of only twoLEDs, an intermediate degree of coupling with lighting of four LEDs, anda preferred degree of coupling being reflected by lighting of all sixLEDs. Using this information, the patient may adjust the position ofhandpiece 151 over the area where implantable device is located toobtain a preferred position for the handpiece, resulting in the shortestrecharging time. In one preferred embodiment, LEDs 168 are replaced withan analog bar display on display 167, which indicates the quality ofcharge coupling.

The Monitoring and Control System

Turning to FIG. 10, the software implementing monitoring and controlsystem of FIG. 1A will now be described. Software 180 comprises a numberof functional blocks, schematically depicted in FIG. 10, including mainblock 184, event logging block 182, data download block 183,configuration setup block 184, user interface block 185, alarm detectionblock 186 including health monitor block 191 and infection predictionblock 192, sensor calibration block 187, firmware upgrade block 188,device identifier block 189 and status information block 190. Thesoftware preferably is written in C++ and employs an object orientedformat. In one preferred embodiment, the software is configured to runon top of a Microsoft Windows® (a registered trademark of MicrosoftCorporation, Redmond, Wash.) or Unix-based operating system, such as areconventionally employed on desktop and laptop computers. The computerrunning monitoring and control system software 180 preferably includes adata port, e.g., USB port or comparable wireless connection, thatpermits handpiece 151 of the charging and communication system to becoupled via port 169. Alternatively, as discussed above, the computermay include a wireless card, e.g., conforming to the IEEE 802.11standard, thereby enabling handpiece 151 to communicate wirelessly withthe computer running software 180. As a further alternative, thecharging and communication system may include telephony circuitry thatautomatically dials and uploads data, such as alarm data, from handpiece151 to a secure website accessible by the patient's physician.

Main block 184 preferably consists of a main software routine thatexecutes on the physician's computer, and controls overall operation ofthe other functional blocks. Main block 184 enables the physician todownload event data and alarm information stored on handpiece 151 to hisoffice computer, and also permits control and monitoring software 180 todirectly control operation of the implantable device when coupled tohandpiece 151. Main block also enables the physician to upload firmwareupdates and configuration data to the implantable device.

Event Log block 182 is a record of operational data downloaded from theimplantable device via the charging and communication system, and mayinclude, for example, pump start and stop times, motor position, sensordata for the peritoneal cavity and bladder pressures, patienttemperature, respiratory rate or fluid temperature, pump outletpressure, humidity, pump temperature, battery current, battery voltage,battery status, and the like. The event log also may include theoccurrence of events, such as pump blockage, operation in boost or jogmodes, alarms or other abnormal conditions.

Data Download block 183 is a routine that handles communication withhandpiece 151 to download data from volatile memory 154 after thehandpiece is coupled to the computer running monitoring and controlsoftware 180. Data Download block 183 may initiates, eitherautomatically or at the instigation of the physician via user interfaceblock 185, downloading of data stored in the event log.

Configuration Setup block 184 is a routine that configures theparameters stored within nonvolatile memory 71 that control operation ofthe implantable device. The interval timing parameters may determine,e.g., how long the processor remains in sleep mode prior to beingawakened to listen for radio communications or to control pumpoperation. The interval timing parameters may control, for example, theduration of pump operation to move fluid from the peritoneum to thebladder and the interval between periodic tick movements that inhibitblockage of the implantable device and peritoneal and bladder catheters.Interval timing settings transmitted to the implantable device frommonitoring and control software 180 also may determine when and howoften event data is written to nonvolatile memory 71, and to configuretiming parameters used by the firmware executed by processor 152 ofhandpiece 151 of the charging and communication system. Block 184 alsomay be used by the physician to configure parameters stored withinnonvolatile memory 71 relating to limit values on operation of processor70 and motor 73. These values may include minimum and maximum pressuresat the peritoneal and bladder catheters, the maximum temperaturedifferential during charging, times when the pump may and may notoperate, etc. The limit values set by block 184 also configureparameters that control operation of processor 152 of handpiece 151.Block 184 also may configure parameters store within nonvolatile memory71 of the implantable device relating to control of operation ofprocessor 70 and motor 73. These values may include target daily volumesof fluid to transport, volume of fluid to be transported per pumpingsession, motor speed and duration per pumping session. Block 184 alsomay specify the parameters of operation of motor 73 during boost mode ofoperation, when coupled to handpiece 151, and shake/jog modes ofoperation when the implantable device is run using battery 74 alone.Such parameters may include motor speed and voltage, duration/number ofrevolutions of the motor shaft when alternating between forward andreverse directions, etc.

User interface block 185 handles display of information retrieved fromthe monitoring and control system and implantable device via datadownload block 183, and presents that information in an intuitive,easily understood format for physician review. As described below withrespect to FIGS. 11 to 15, such information may include status of theimplantable device, status of the charging and control system, measuredpressures, volume of fluid transported per pumping session or per day,etc. User interface block 185 also generates user interface screens thatpermit the physician to input information to configure the intervaltiming, limit and pump operation parameters discussed above with respectto block 184.

Alarm detection block 186 may include a routine for evaluating the dataretrieved from the implantable device or charging and communicationsystem, and flagging abnormal conditions for the physician's attention.For example, alarm detection block 186 may include health monitor block191, which is configured to alert the physician to any changes in thepatient's health that may warrant changing the volume, time, and/orfrequency provided to the patient's peritoneum. For example, if dataprovided by the implantable device 20 indicate a buildup of products,then the physician may increase the volume, time, and/or frequencyprovided to and withdrawn from the patient's peritoneum. Or, if dataprovided by the implantable device 20 indicate a relatively low volumeof products, then the physician may decrease the volume, time, and/orfrequency provided to and withdrawn from the patient's peritoneum.

Alarm detection block 186 also, or alternatively, may include infectionprediction block 192, which is configured to predict or detect infectionbased on, for example, one or more of an increase in the patient'stemperature above a predefined threshold, an increase in the patient'srespiratory rate above a predefined threshold, and/or an increase in thefluid above a predefined threshold. Such flags may be communicated tothe physician by changing status indicators presented by user interfaceblock 185, or by displaying to the physician specific information aboutincreases in the patient's temperature, respiratory rate, or fluidviscosity via user interface block 185.

Sensor calibration block 187 may include a routines for testing ormeasuring drift, of sensors 70, 78-81 employed in the implantabledevice, e.g., due to aging or change in humidity. Block 187 may thencompute offset values for correcting measured data from the sensors, andtransmit that information to the implantable device for storage innonvolatile memory 71. For example, pressure sensors 104 a-104 d mayexperience drift due to aging or temperature changes. Block 187accordingly may compute offset values that are then transmitted andstored in the implantable device to account for such drift.

Firmware upgrade block 188 may comprise a routine for checking theversion numbers of the processor or motor controller firmware installedon the implantable device and/or processor firmware on charging andcommunication system, and identify whether upgraded firmware exists. Ifso, the routine may notify the physician and permit the physician todownload revised firmware to the implantable device for storage innonvolatile memory 71 or to download revised firmware to the chargingand communication system for storage in nonvolatile memory 153.

Device identifier block 189 consists of a unique identifier for theimplantable device that is stored in nonvolatile memory 71 and a routinefor reading that data when the monitoring and control system is coupledto the implantable device via the charging and communication system. Asdescribed above, the device identifier is used by the implantable deviceto confirm that wireless communications received from a charging andcommunication system are intended for that specific implantable device.Likewise, this information is employed by handpiece 151 of the chargingand communication system in determining whether a received message wasgenerated by the implantable device associated with that handpiece.Finally, the device identifier information is employed by monitoring andcontrol software 180 to confirm that the handpiece and implantabledevice constitute a matched set.

Status information block 190 comprises a routine for interrogatingimplantable device, when connected via handpiece 151, to retrievecurrent status date from the implantable device, and/or handpiece 151.Such information may include, for example, battery status, the date andtime on the internal clocks of the implantable device and handpiece,version control information for the firmware and hardware currently inuse, and sensor data.

Referring now to FIGS. 11-15, exemplary screen shots generated by userinterface block 187 of software 180 are described for a treatmentsystem. FIG. 11 shows main screen 200 that is displayed to a physicianrunning monitoring and control software 180. Main screen 200 includes astatus area that displays status information retrieved from theimplantable device and the charging and communication system by theroutine corresponding to block 190 of FIG. 10. More particularly, thestatus area includes status area 201 for the charging and communicationsystem (referred to as the “Smart Charger) and status area 202 for theimplantable device (referred to as the “ALFA Pump”). Each status areaincludes an icon showing whether the respective system is operatingproperly, indicated by a checkmark, the device identifier for thatsystem, and whether the system is connected or active. If a parameter isevaluated by the alarm detection block 186 to be out of specification,the icon may instead include a warning symbol. Menu bar 203 identifiesthe various screens that the physician can move between by highlightingthe respective menu item. Workspace area 204 is provided below thestatus area, and includes a display that changes depending upon the menuitem selected. Below workspace area 204, navigation panel 205 isdisplayed, which includes the version number of software 180 and a radiobutton that enables the displays in workspace area 204 to be refreshed.

In FIG. 11, the menu item “Information” with submenu item “Implant” ishighlighted in menu bar 203. For this menu item selection, workspacearea 204 illustratively shows, for the implantable device, batterystatus window 204 a, measured pressures window 204 b and firmwareversion control window 204 c. Battery status window 204 a includes anicon representing the charge remaining in battery 74, and may bedepicted as full, three-quarters, one-half, one-quarter full or show analarm that the battery is nearly depleted. The time component of window204 a indicates the current time as received from the implantabledevice, where the date is expressed in DD/MM/YYYY format and time isexpressed in HR/MIN/SEC format based on a 24 hour clock. Measuredpressures window 204 b displays the bladder pressure, peritonealpressure and ambient pressures in mBar measured by sensors 104 a, 104 band 104 d respectively (see FIG. 6A). Version control window 204 cindicates the firmware version for processor 70, for the motorcontroller, and the hardware version of the implantable device. Patientparameters window 204 d displays the patient's temperature, respiratoryrate, and fluid viscosity. Note that if implantable device includedother types of sensors, e.g., sensors that measure the levels ofproducts in the fluid, then the parameters measured by such sensorscould also be displayed in window 204 d.

Alarm condition window 204 e displays any changes in parameters that mayindicate a change in the patient's health, such as the possibledevelopment of an infection or an improvement or worsening of thepatient's health (Blocks 191 and 192 in FIG. 10). For example, asillustrated, alarm condition window 204 e may alert the physician thatthe patient's temperature is abnormally high, so that the physician thenmay follow up with the patient regarding the possibility of infection.In some embodiments, based on information displayed in windows 204 b,204 d, and/or 204 e, the physician may adjust the operating parametersof the pump, e.g., using the interface described further below withreference to FIG. 14.

Turning to FIG. 12, screen display 206 corresponding to selection of the“Smart Charger” submenu item in FIG. 11 is described. FIG. 12 includesstatus area 201 for the charging and communication system, status area202 for the implantable device, menu bar 203, workspace area 204, andnavigation panel 205 as discussed above with respect to FIG. 11. Screendisplay 206 differs from screen display 200 in that the “Smart Charger”submenu item is highlighted, and workspace area 204 displays, for thecharging and control system, battery status window 207 a and versioncontrol window 207 b. Battery status window 207 a includes an iconrepresenting the charge remaining in battery 157, and may be depicted asfull, three-quarters, one-half, one-quarter full or show an alarm thatthe battery is nearly depleted. The time component of window 207 aindicates the current time as received from handpiece 151, where thedate is expressed in DD/MM/YYYY format and time is expressed inHR/MIN/SEC format based on a 24 hour clock. Version control window 207 bindicates the firmware version for processor 152, and the hardwareversion of the charging and control system.

Referring now to FIG. 13, screen display 208 corresponding to selectionof the “Download” menu item in FIG. 11 and “Log Files” submenu item isdescribed, and implements the functionality of block 183 of software180. FIG. 13 includes status area 201 for the charging and communicationsystem, status area 202 for the implantable device, menu bar 203,workspace area 204, and navigation panel 205, all as discussed above.Screen display 208 differs from the “Information” screen display in thatthe “Log Files” submenu item is highlighted, and workspace area 204displays download progress window 209 a and storage path window 209 b.Window 209 a includes the path for the directory to which event logs maybe downloaded from the implantable device via the charging andcommunication system. Window 209 a also includes an “Open DownloadFolder” radio button that allows the physician to choose the directorypath to which the event logs are downloaded, and a progress bar that isupdated to reflect the amount of data downloaded. Window 209 b includesa radio button that can be activated to download the event log to thepath specified in window 209 a, and also includes an “Abort” radiobutton to interrupt the download process.

FIG. 14 is an exemplary depiction of screen display 210, correspondingto selection of the “Pump Settings” menu item in FIG. 11 and “FluidTransport” submenu item, and implements the functionality of blocks 184and 190 of software 180. FIG. 14 includes status area 201 for thecharging and communication system, status area 202 for the implantabledevice, menu bar 203, workspace area 204, and navigation panel 205, allas discussed above. Screen display 210 differs from the “Information”screen displays in that the “Fluid Transport” submenu item ishighlighted, and workspace area 204 includes session volume window 211a, fluid transport program window 211 b, minimum daily volume window 211c, pressure window 211 d, and a radio button in navigation panel 205that permits values entered in windows 211 a, 211 b and 211 d to betransmitted and stored in nonvolatile memory 71 of the implantabledevice.

Session volume window 211 a displays the current setting for the maximumdaily volume to be pumped by the implantable device, the interval timebetween pumping sessions, the times of the day that the pump may beactivated, the total daily pump time and the session volume per pumpingsession. The maximum daily volume displayed in window 211 a correspondsto the upper limit of fluid that the pump will transfer to peritoneumand/or to the bladder in a 24-hour period, although the actual volumepumped may be lower if the implantable device detects low fluidconditions. The physician may initially set this value based onperceived patient health, and the value may have an allowed range, e.g.,of 20 ml to 4000 ml. The dwell time displayed in window 211 a allows thephysician to set the amount of time to remain in the peritoneum. Theinterval time displayed in window 211 a allows the physician to set thefrequency pumped into the peritoneum to the bladder (as well as from thereservoir to the peritoneum). The daily volume and interval times areused by the configuration setup routine (block 184 of FIG. 10) tocompute the session volume, which preferably is in a range of 500 ml to2,500 ml. The time segments that the pump may be active, displayed inwindow 211 a, optionally may be used define the timeframes during whichthe implantable device can actively move fluid to the bladder; outsideof these time segments, the implantable device will not move fluid butmay implement the pump tick operation described above to turn the gearson a regular basis to prevent clogging of the gears. Depending on theperceived health of the patient, the physician may set the time segmentssuch that the pump may operate at all hours of the day or night, aspreservation of health may override convenience in some circumstances.The daily pump time displayed in window 211 a is shown in read-onlyformat because it is the aggregate of the time segments entered in thetime segments boxes. Finally, the session volume displayed in window 211a is computed by block 183 as the amount of fluid transferred to thebladder in a single pumping session.

Fluid transport program window 211 b displays the status of the programcontrolling operation of the pump of the implantable device based on theparameters set using block 184 of software 180. In case pump activitymust be stopped for any reason, the fluid transport program can bestopped by clicking the “Off” button in window 211 b, which will causethe Pump to stop pumping until it is manually switched back on. In oneembodiment, the fluid transport program may switched on again bypressing the “On” button in window 211 b. Because the implantable devicepreferably is implanted with the pump turned off, the physician orsurgeon may use window 211 b to turn on the fluid transport programafter the implantable device is first implanted.

Minimum daily volume window 211 c displays the expected amount of fluidto be pumped to the bladder by the implantable device, and is computedby the configuration setup routine as the session volume times thenumber of sessions per day, based on the length of the prescribed timesegments and interval timing input in window 211 a.

Pressure window 211 d of FIG. 14 permits the physician to input valuesof maximum bladder pressure and minimum peritoneal pressure that areused to control operation of the implantable pump. Thus, for example,processor 70 will command motor 73 to cease a current pumping session,or to skip a planned pumping session during the time segments identifiedin window 211 a, if the bladder pressure detected by the pressuresensors exceeds the value specified in window 211 d. Likewise, processor70 will command motor 73 to cease a current pumping session, or to skipa planned pumping session during the time segments identified in window211 a, if the peritoneal pressure detected by the pressure sensors isless than the value specified in window 211 d. If configured to operatein the above-described manner, the implantable device will neither causepatient discomfort by overfilling the patient's bladder, nor cause theperitoneal cavity to become excessively dry.

Referring now to FIG. 15, an exemplary depiction of screen display 212,corresponding to selection of the “Test” menu item in FIG. 11 and“Manual Test Run” submenu item is described. FIG. 15 includes statusarea 201 for the charging and communication system, status area 202 forthe implantable device, menu bar 203, workspace area 204, and navigationpanel 205, all as discussed above. Screen display 212 differs from the“Information” screen displays in that the “Manual Test Run” submenu itemis highlighted, and workspace area 204 includes manual pump cycle window213. Manual pump cycle window 213 includes radio button “Start Test”which transmits a command to the implantable device via the charging andcommunication system to cause processor 70 to activate the pump for apredetermined period of time, e.g., a few seconds. Processor 70 receivespositional data from the Hall Effect sensors in motor 73 and measuredpressure data across pressure sensors 104 c and 104 d. Processor 70computes a session volume and relays that information via the chargingand communication system back to software 10, which compares themeasured data to a target session volume and provides a test result,e.g., percentage of session target volume achieved or pass/fail icon.The measured session volume, session target volume and test result aredisplayed in window 213.

While various illustrative embodiments of the invention are describedabove, it will be apparent to one skilled in the art that variouschanges and modifications may be made therein without departing from theinvention. For example, system 10 may be modified to include additionaldevices configured to assess the physical and/or mental health of thepatient, such as a hand-held biosensor that measures the levels ofproducts, e.g., ammonia, c-reactive protein, plasma renin, serum sodium,serum creatinine, prothrombin time, and/or bilirubin, in a drop of thepatient's blood. Or, for example, system 10 may be modified to include ahand-held or computer-based device that presents the patient withpsychometric tests that measure the psychological health orelectrophysiological activity of the subject. Such devices may beconfigured to wirelessly provide results to monitoring and controlsystem 40 for the physician to use in assessing the patient's health andthe possible need to adjust the operating parameters of implantabledevice 20. The appended claims are intended to cover all such changesand modifications that fall within the true spirit and scope of theinvention.

1. A method of managing fluid in a patient, the method comprising:inductively charging, by an external device through skin of the patient,an implanted device within the patient that is configured to transportfluid from a peritoneal cavity of the patient to a bladder of thepatient; receiving, by the external device, an instruction from a remotecomputer to control transportation of the fluid from the peritonealcavity to the bladder of the patient by the implanted device; andwirelessly transmitting, by the external device through the skin of thepatient, the instruction to the implanted device.
 2. The method of claim1, further comprising: wirelessly receiving, by the external devicethrough the skin of the patient, information from the implanted device;and transmitting, by the external device, the information to the remotecomputer.
 3. The method of claim 1, wherein the instruction comprisesone or more of: a target amount of the fluid to move daily, a targetamount of fluid to move per motor actuation, an interval between pumpactuations, or a limit on peritoneal cavity pressure, bladder pressure,pump pressure, or battery temperature.
 4. The method of claim 1, whereinthe instruction controls operation of the implanted device not to movefluid during a specified period or to defer pump actuation if thepatient is asleep.
 5. The method of claim 1, wherein the instructioncontrols operation of the implanted device to start or stop a pump, tooperate the pump in reverse, or to operate the pump at high power tounblock the pump or associated catheters.
 6. The method of claim 1,wherein the instruction reduces the patient's volume of fluid.
 7. Themethod of claim 1, wherein the instruction reduces the levels ofproducts in the patient's fluid.
 8. The method of claim 7, wherein theproducts comprise serum sodium.
 9. The method of claim 1, furthercomprising displaying, by the external device, light signals indicatinga degree of magnetic coupling between the external device and theimplanted device when inductively charging the implanted device.
 10. Themethod of claim 1, further comprising infusing the fluid into theperitoneum from an external reservoir via a catheter.
 11. An externaldevice for managing fluid in a patient, the external device comprising:an inductive charger configured to charge, through skin of the patient,an implanted device within the patient that is configured to transportfluid from a peritoneal cavity of the patient to a bladder of thepatient; one or more transceivers; and a processor configured to receivean instruction from a remote computer, via the one or more transceivers,to control transportation of the fluid from the peritoneal cavity to thebladder of the patient by the implanted device, and to wirelesslytransmit, via the one or more transceivers, the instruction to theimplanted device through the skin of the patient.
 12. The device ofclaim 11, wherein the processor further is configured to: wirelesslyreceive, via the one or more transceivers, information from theimplanted device through the skin of the patient; and transmit, via theone or more transceivers, the information to the remote computer. 13.The device of claim 11, wherein the instruction comprises one or moreof: a target amount of the fluid to move daily, a target amount of fluidto move per motor actuation, an interval between pump actuations, or alimit on peritoneal cavity pressure, bladder pressure, pump pressure, orbattery temperature.
 14. The device of claim 11, wherein the instructioncontrols operation of the implanted device not to move fluid during aspecified period or to defer pump actuation if the patient is asleep.15. The device of claim 11, wherein the instruction controls operationof the implanted device to start or stop a pump, to operate the pump inreverse, or to operate the pump at high power to unblock the pump orassociated catheters.
 16. The device of claim 11, wherein theinstruction reduces the patient's volume of fluid.
 17. The device ofclaim 11, wherein the instruction reduces the levels of products in thepatient's fluid.
 18. The device of claim 17, wherein the productscomprise serum sodium.
 19. The device of claim 11, further comprisingone or more lights configured to indicate a degree of magnetic couplingbetween the external device and the implanted device when inductivelycharging the implanted device.